package insta.project;

import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;

public class CoverFlow extends Gallery {
	private static Camera mCamera = new Camera();
	private static final int mMaxRotationAngle = 70;
	private static final int mMaxZoom = -180;
	private int centre;

	/* Construction */
	public CoverFlow(Context context) {
		super(context);
		this.setStaticTransformationsEnabled(true);
	}

	public CoverFlow(Context context, AttributeSet attrs) {
		super(context, attrs);
		this.setStaticTransformationsEnabled(true);
	}

	public CoverFlow(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		this.setStaticTransformationsEnabled(true);
	}

	/* *********************************************************************** */

	/* Renvoie le centre du coverflow */
	private int getCentreCoverFlow() {
		return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();
	}

	/* Renvoie le centre de la vue (avec le padding par exemple) */
	private static int getCentreVue(View view) {
		return view.getLeft() + view.getWidth() / 2;
	}

	protected boolean getChildStaticTransformation(View child, Transformation t) {
		final int childCenter = getCentreVue(child);
		final int childWidth = child.getWidth();
		
		int rotationAngle = 0;
		t.clear();
		t.setTransformationType(Transformation.TYPE_MATRIX);

		if (childCenter == centre) {
			transformImageBitmap((ImageView) child, t, 0);
		} else {
			rotationAngle = (int) (((float) (centre - childCenter) / childWidth) * mMaxRotationAngle);
			
			if (Math.abs(rotationAngle) > mMaxRotationAngle) {
				rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;
			}
	
			transformImageBitmap((ImageView) child, t, rotationAngle);
		}
		
		return true;
	}

	/* Callback pour le redimensionnement */
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		centre = getCentreCoverFlow();
		super.onSizeChanged(w, h, oldw, oldh);
	}

	/* L'effet coverflow */
	private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) {
		mCamera.save();
		final Matrix imageMatrix = t.getMatrix();
		final int imageHeight = child.getLayoutParams().height;
		final int imageWidth = child.getLayoutParams().width;
		final int rotation = Math.abs(rotationAngle);
		mCamera.translate(0.0f, 0.0f, 100.0f);

		if (rotation < mMaxRotationAngle) {
			float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));
			mCamera.translate(0.0f, 0.0f, zoomAmount);
		}
		
		mCamera.rotateY(rotationAngle);
		mCamera.getMatrix(imageMatrix);
		imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
		imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));
		mCamera.restore();
	}
}
